Apparatus of this type may be seen in, for example, US Publication No. 2008/0063223, WO 2008/054921, US Publication No. 2008/0170732, WO 2006/083834, US Publication No. 2006/0159298, US Publication No. 2006/0088176, EP 1795160, and WO 2007/115304.
Hitherto, when providing multiple receiver systems in e.g. hearing aids, a tubing or spout is desired for providing additional acoustical filtering of the output sound in order to, for example, provide the filtering brought about by the head shape of the person when a user having normal hearing listens to a sound. This filtering is not automatically provided when using a hearing aid.
Without such tubing or spouts, the so-called second peak is usually above or close to 10 kHz. In a number of desired applications, this peak preferably is somewhere between 4 and 7-8 kHz. By creating the tubing between the two single receivers, the second peak can be created again.